surprised fans attending 's concert in Miami, Florida over the weekend when he made an unannounced appearance onstage. However, not everything went according to his plan. The Canadian heartthrob forgot some lyrics while he joined the petite diva during the performance of "Love Me Harder".

In a video taken and shared by a concertgoer, the crowd cheered loudly when Bieber emerged on the stage after Grande finished singing the first chorus. He sang the lines originally sung by and that's when he messed up the lyrics.